Paper magazine for a recording paper roll and recording paper roll

ABSTRACT

A roil of a recording paper is rotatably contained in a paper magazine. The magazine is provided with a mouth through which the recording paper is drawn out and fed to a printer. A leading edge of the recording paper is adapted to come into contact with an outer periphery of the roll by a contacting device. The remainder of the roll is indicated by an indicating device. The mouth of the magazine is opened and closed with a shutter unit. The inside of the magazine tightly closed with the shutter unit is kept at constant humidity by a humidity conditioning paper. On the other hand, the roll is caught between a pair of flanges. One of the flanges is biased by plate springs toward the other of the flanges so that the roll is held in the magazine without looseness.

This is a divisional of U.S. application Ser. No. 09/557,876, now U.S.Pat. No. 6,357,686 filed Apr. 24, 2000; which is a divisional of U.S.application Ser. No. 08/895,458, now U.S. Pat. No. 6,089,487, filed Jul.16, 1997, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a paper magazine for a recording paperroll such as a roll of a film-like thermal recording paper, and to arecording paper roll for keeping humidity of the paper magazine at aconstant level.

2. Description of the Related Art

For example, in a color thermal printer, a color thermal recording paperis used and three colors are recorded in order to record a full colorimage. As shown in FIG. 15, the color thermal recording paper 110 isprovided with a cyan heat sensitive color layer 102, a magenta heatsensitive color layer 103, a yellow heat sensitive color layer 104, anda protect layer 105 which are stacked in order on a support member 101utilizing a resin-coated paper. The yellow heat sensitive color layer104, which is the uppermost layer among the color layers, has thehighest heat sensitivity. The cyan heat sensitive color layer 102, whichis the lowermost layer, has the lowest heat sensitivity. Each of thecolor layers is recorded in order from the uppermost layer. After ayellow image is recorded, near ultraviolet radiation of 420 nm isapplied to fix the yellow image optically. Accordingly, non-coloredingredient of the yellow heat sensitive color layer 104 is not coloredwhen thermal recording for the magenta heat sensitive color layer 103 iscarried out. Similarly, after the recording for the magenta heatsensitive color layer 103 was carried out, ultraviolet radiation of 365nm is applied to fix a magenta image optically.

For a personal-use thermal printer in which the amount of prints issmall, cut papers are used. The paper is cut in a predetermined sizebeforehand. However, a for business-use thermal printer in which theamount of prints is large, it is suggested that a roll-like colorthermal recording paper is used and cut as a sheet after recording. Forexample, Japanese Patent Laid-Open Publication No. 6-79893 discloses acolor thermal printer in which a pinch roller and a thermal head aredisposed at an outer periphery of a platen roller. The color thermalrecording paper is moved half round the platen roller so as to be foldedback in a U-like shape. Successively, the color thermal recording paperis sent to an optical fixing unit. The fixing unit is constituted of twoultraviolet lamps and arranged such that the ultraviolet radiation fromthe lamp crosses the recording paper. One of the ultraviolet lamps isfor fixing the yellow image and applies the near ultraviolet radiationof 420 nm to the recording paper. The other of the ultraviolet lamps isfor fixing magenta and applies the ultraviolet radiation of 365 nm tothe recording paper. At the downstream side, a cutter is disposed infront of a paper discharge port.

In this color thermal printer, the color thermal recording paper drawnout from the thermal recording paper roll is advanced and pulled back ata printing section. The advancement and the pulling back are performedone after the other in order to record a full color image in three-colorframe sequential process. At the outset, the recording paper is advancedfrom the paper roll by a predetermined amount. After that, the platenroller and the paper roll are rotated in the reverse direction to pullback the recording paper. During the first pulling back, the recordingpaper is pressed and heated with the thermal head to record a yellowimage in a record area line by line.

The recording paper is advanced from the paper roll again. At this time,the ultraviolet lamp for yellow image is turned on to fix the yellowheat sensitive color layer. During the second pulling back of therecording paper, the magenta image is recorded with the thermal head.After that, the recording paper is advanced again. At this time, theultraviolet lamp for the magenta image is turned on to fix the magentaheat sensitive color layer. During the third pulling back, the cyanimage is recorded in the cyan heat sensitive color layer one line by oneline. After recording the cyan image, the recording paper is advancedfrom the paper roll and cut with the cutter as a sheet. The sheet isdischarged and the thermal recording of one sheet is completed.

In case of the color thermal printer using the roll-like color thermalrecording paper as described above, an amount of recording sheets cutfrom a thermal recording paper roll is very large so that it is possibleto carry out a great number of prints without exchange of the thermalrecording paper roll. However, if the thermal recording paper roll istaken out from a light shielding sack, and a dampproofing sack and soforth is set in the color thermal printer for a long time, the paperroll is exposed to the light entering the thermal printer so that thecolor ability thereof is reduced. Moreover, the color property of therecording paper is changed by the influence of humidity in the colorthermal printer. Thus, it becomes impossible to color in a desireddensity. Further, if the ultraviolet ray from a fluorescent lamp and soon enters the color thermal printer, the color property is changed alsoat this time.

In order to prevent the color property of the recording paper fromchanging, it is considered, for example, that the remainder of the paperroll is taken out from the color thermal printer and contained in adampproofing sack, a dampproofing box and so forth whenever the printingis over. However, it takes a lot of time and labor to do that. Further,the photosensitive thermal recording paper is exposed to the outsidelight in the course of containing it.

Thus, it is desirable to protect the thermal recording paper rollagainst the humidity and ultraviolet rays by containing it in a papermagazine. In this case, it is desired that after the printing was over,the recording paper sent in the color thermal printer is drawn back inthe paper magazine and a draw-out mouth of the paper magazine is closed.

By using such a paper magazine, the influence of ultraviolet rays may beprevented. However, it is difficult to shut the paper magazine tightlyand perfectly so that little air enters the paper magazine. Of course,the draw-out mouth is opened during the printing so that the air entersthe paper magazine during that operation. If the recording paper iscontained in the paper magazine for a long time, humidity for therecording paper changes gradually due to the air entering the papermagazine. At this time, the influence of humidity for the recordingpaper is different in accordance with a portion thereof. In other words,influences of the humidity for a roll portion and a leading edge portionapart from the roll portion are different.

At the roll portion, a color face of the color thermal recording papercontacts a rear face of one-round inner color thermal recording paper sothat the color face is hardly affected by the dampness of the airentering the paper magazine. However, at the leading edge portion apartfrom the roll portion, the color face is exposed in the paper magazineso that the color face is affected by the dampness in the papermagazine. When the printing is carried out for such a color thermalrecording paper, color densities are different relative to the leadingedge portion affected by the dampness and the roll portion hardlyaffected by the dampness.

In the case of using the paper magazine, it is desirable that a mainbody of the paper magazine is made of light shielding material so as notto expose the thermal recording paper roll to the natural light and thelight from a fluorescent lamp. However, if the paper magazine is made ofthe light shielding material, there arises a problem in that theremainder of the paper roll contained in the magazine can not beobserved from the outside. If the remainder of the paper roll is notknown, it is impossible to foresee the exchange timing thereof. Thus,there arise problems in that the recording paper runs out during theprinting, and that preparation of the paper roll is behind.

By the way, FIG. 16 is a graph showing a color property of the colorthermal recording paper. Full lines show the color properties at 60% RHwhich is normal humidity at 25° C. Under an environment that thehumidity is higher than that, the amount of moisture contained in therecording paper increases. As shown by dashed lines in FIG. 16, if aprescribed thermal energy is applied to the recording paper, each colorof yellow (Y), magenta (M) and cyan (C) colors in paler density than anoriginal color density. Under an environment that the humidity is lowerthan the normal humidity, the amount of moisture contained in therecording paper decreases rather than an amount relative to the normalhumidity. In this case, as shown by broken lines in FIG. 16, if aprescribed thermal energy is applied to the recording paper, each colorof Y, M and C colors in darker density than the original color density.

When the thermal recording paper roll is contained in the papermagazine, as the paper magazine does not have a humidity adjustingability, the paper roll is not kept at the normal humidity. For example,if an outer environment of the paper magazine is in a high humiditystate or a low humidity state when the paper roll is set in the papermagazine, the inside of the paper magazine is adapted to be kept in astate of high humidity or low humidity. Further, of course, the draw-outmouth for the recording paper is opened during the printing. Thus, thedamp or the dry air enters the paper magazine through the draw-out mouthwhen the printing is carried out for a long time. By the outside airentering the magazine, the recording paper comes into a state of highhumidity or low humidity gradually while it is contained in the papermagazine.

A conventional paper magazine is constituted of a magazine main bodyformed with an elongated paper feed mouth and a lid rotatably attachedto the magazine main body via a hinge. A recording paper roll is woundaround a cylindrical core made of paper or plastic. When the paper rollis loaded in the paper magazine, a pair of flanges are attached to thecore. Each of the flanges is provided with a shaft portion passingthrough a flange portion. A support portion is provided on an inside ofthe flange portion and fitted into the core. The shaft portion is put ina bearing of the magazine main body. The lid is closed after loading thepaper roll.

However, in the conventional paper magazine, if there is loosenessbetween the bearing of the magazine main body and the flange, therecording paper drawn out from the paper magazine is shifted from theregular position in width direction. Due to a gap of position, an imageis not correctly printed at a predetermined position of the recordingpaper.

Moreover, the paper roll is superfluously rotated by inertia after thedrawing operation of the recording paper was stopped. And the paper rollis sometimes rotated by vibration and so forth during the printing.Thus, conventionally, a clutch device such as a friction clutch and soon is attached to a recording paper roll to give a back tension so thatthe paper roll is prevented from rotating inadvertently. However, uponusing the clutch device, the structure of the paper magazine becomescomplicated and the cost of it increases.

SUMMARY OF THE INVENTION

In view of the foregoing, it is a primary object of the presentinvention to provide a paper magazine for a recording paper roll inwhich the paper roll is kept in uniform humidity up to a leading edgeportion thereof.

It is a second object of the present invention to provide a papermagazine for a recording paper roll in which a remainder of the paperroll is easily known from an outside of the paper magazine.

It is a third object of the present invention to provide a papermagazine for a recording paper roll in which the paper roll is set in aprinter in a usable state.

It is a fourth object of the present invention to provide a papermagazine for a recording paper roll in which an inside of the papermagazine is adapted to be kept at a constant humidity.

It is a fifth object of the present invention to provide a recordingpaper roll for keeping the inside of the paper magazine at a constanthumidity.

It is a sixth object of the present invention to provide a papermagazine for a recording paper roll in which looseness and racing of thepaper roll are prevented by simple structure and at low cost.

In order to achieve the above and other objects, the paper magazine forthe paper roll comprises an endless belt movably arranged around adriving roller, a bias roller and a driven roller which are disposed ina triangular form. The bias roller is urged by a spring so that constanttension is applied to the endless belt. Thus, although a diameter of arecording paper roll changes, the endless belt always contacts a part ofan outer periphery of the paper roll tightly. After printing is over,the endless belt is rotated in reverse direction to wind up a leadingedge of the recording paper into the paper magazine. The leading edge ispressed by the endless belt and tightly contacts the outer periphery ofthe paper roll.

In other embodiment, the paper magazine is provided with a rollremainder indicator for indicating the remainder of the paper roll. Theindicating device comprises an arm, a coil spring, an indicating memberand a scale plate. The arm contacts the outer periphery of the paperroll. The coil spring biases the arm so as to press it to the outerperiphery of the paper roll. The indicating member is for pointing outan amount of the remainder and is fixedly secured to one end of the arm.The scale plate is stuck on the outside of the paper magazine. The armhas a roller rotatably attached to the other end of the arm. The rollercontacts the outer periphery of the paper roll. The arm rotates inaccordance with the diameter of the paper roll so that a position of theindicating member is changed. The remainder of the recording paper isindicated due to the position of the scale plate pointed by theindicating member.

In another embodiment, the paper magazine is provided with a shutterunit for closing a draw-out mouth formed in a lower portion of the papermagazine in light-tight state. The shutter unit comprises a shutterbeing movable between a closed position in which the draw-out mouth islight-tightly closed and an open position in which the draw-out mouthemerges. The shutter is moved along a support frame. The shutter unit isoperated by an operating device attached to the printer. Alternatively,the shutter unit is operated in association with the attachment anddetachment of the paper magazine.

Further, in this paper magazine, a humidity conditioning paper is set.The humidity conditioning paper performs absorption of moisture when theinterior humidity of the paper magazine is higher than the normalhumidity. When the interior humidity is lower than the normal humidity,humidification is performed by the humidity conditioning paper.Accordingly, the interior humidity of the paper magazine is always keptat normal humidity. The recording paper is not affected by a change ofthe humidity.

In another embodiment, the paper magazine is provided with a pluralityof plate springs attached around a bearing for the paper roll. The platesprings are disposed on a concentric circle centering around arotational center of the paper roll. The plate springs contact one ofthe flanges of the paper roll and push it toward the other of theflanges. Thus, the paper roll is kept in the paper magazine withoutlooseness so that the recording paper is stably drawn out from the papermagazine without meandering.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will becomeapparent from the following detailed description of the preferredembodiments of the invention when read in conjunction with theaccompanying drawings, in which:

FIG. 1 is a perspective view showing a paper magazine for a recordingpaper roll according to the present invention;

FIG. 2 is a sectional view of the paper magazine shown in FIG. 1;

FIGS. 3A and 3B are schematic illustrations showing a structure of acolor thermal printer;

FIGS. 4A and 4B are explanatory illustrations showing works of the papermagazine;

FIG. 5 is an explanatory illustration showing a second embodiment of thepaper magazine according to the present invention;

FIGS. 6A and 6B are explanatory illustrations showing a third embodimentof the paper magazine according to the present invention;

FIG. 7 is a perspective view showing a fourth embodiment of the papermagazine according to the present invention;

FIGS. 8A and 8B are explanatory illustrations showing works of the papermagazine in FIG. 7;

FIGS. 9A and 9B are explanatory illustrations showing a fifth embodimentof the paper magazine according to the present invention;

FIG. 10 is a perspective view showing a sixth embodiment of the papermagazine according to the present invention;

FIG. 11 is a perspective view showing a thermal recording paper roll, acore of which is made of humidity conditioning material;

FIG. 12 is a perspective view showing a seventh embodiment of the papermagazine according to the present invention;

FIG. 13 is a sectional view of the paper magazine shown in FIG. 12;

FIG. 14 is a perspective view showing a eighth embodiment of the papermagazine according to the present invention;

FIG. 15 is an explanatory illustration showing an example of layerconstruction of a color thermal recording paper; and

FIG. 16 is a graph showing a relationship between thermal energy andcolor density.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 is a perspective view of a paper magazine for a thermal recordingpaper roll embodying the present invention and FIG. 2 is a sectionalview thereof A magazine main body 1 has a box-like shape and comprisesan upper case 3 and a lower case 4, each of which is made of lightshielding resin. The upper case 3 and the lower case 4 are swingablyconnected by a hinge to each other at a contact portion 5. Packing 6 isprovided at the contact portion 5 and other contact portion of the uppercase 3 and the lower case 4. The packing 6 keeps an inside of themagazine main body 1 in a light-tight state and prevents moisture andultraviolet rays from entering the inside of the magazine main body 1.

A roll support shaft 7 is removably attached around a center of thepaper magazine 2. The roll support shaft 7 is inserted into a core 12 aof a thermal recording paper roll 12. The paper roll 12 is a roll of afilm-like color thermal recording paper 11. The paper roll 12 isrotatably supported in the paper magazine 2. By the way, as well known,the color thermal recording paper 11 is a recording paper in which acyan heat sensitive color layer, a magenta heat sensitive color layerand a yellow heat sensitive color layer are stacked in order. Each ofthe color layers has heat sensitivity being different from each other.The yellow heat sensitive color layer loses its color ability byapplying near ultraviolet rays of 420 nm. The magenta heat sensitivecolor layer loses its color ability by applying ultraviolet rays of 365nm.

At a lower portion of the paper magazine 2, a draw-out mouth 8 isprovided. The draw-out mouth 8 is for drawing out the recording paper 11and supplying it to a color thermal printer. Further, at the outside ofthe draw-out mouth 8, a shutter unit 9 for closing the draw-out mouth 8in light-tight manner is provided. The shutter unit 9 is constituted ofa shutter 15, a support frame 16, a spring 17 and a packing 18. Theshutter 15 is movable in up-and-down direction. The support frame 16supports both sides of the shutter 15. The spring 17 biases the shutter15 in the down direction. The packing 18 is disposed between the shutter15 and an outer face of the draw-out mouth 8.

The shutter 15, the lower portion of which is crooked, has an L-likeshape and is movable between a closed position and an open positionalong the support frame 16. When the shutter 15 is set in the closedposition, a front side of the draw-out mouth 8 is light-tightly coveredtherewith. When the shutter 15 is set in the open position, the shutter15 is positioned above the draw-out mouth 8 so that the draw-out mouth 8is exposed. The packing 18 contacts the edge of the draw-out mouth 8 andthe inner face of the shutter 15 when the shutter 15 is set in theclosed position so that the light and damp are prevented from enteringthe paper magazine 2 through a gap between the draw-out mouth 8 and theshutter 15. By the way, the shutter 15 is opened and closed by a shutteroperating device attached to a color thermal printer as described below.

A contact conveying device 51 is provided along the paper roll 12 fromvicinity of the draw-out mouth 8 to vicinity of the contact portion 5.The conveying device 51 makes the recording paper 11 contact an outerperiphery of the paper roll 12 up to leading edge portion of therecording paper 11. Further, the conveying device 51 has a function thatthe recording paper 11 is sent to the thermal printer from the paperroll 12 via the draw-out mouth 8 and wound back in the magazine mainbody I up to the leading edge portion thereof after printing. Theconveying device 51 is constituted of a driving roller 52, a bias roller53, a driven roller 54 and an endless belt 55. The driving roller 52 isdisposed near the draw-out mouth 8. The bias roller 53 is disposed nearthe corner of the lower case 4. The driven roller 54 is disposed nearthe inside of the contact portion 5. The endless belt 55 is movablyattached to the three rollers 52, 53 and 54.

One end of an shaft 52 a of the driving roller 52 penetrates the lowercase 4 and extends to the outside thereof. A driven gear 22 is fixedlysecured to the one end of the shaft 52 a. The driven gear 22 meshes witha driving gear 28 when the paper magazine 2 is loaded in the colorthermal printer. The driving gear 28 is rotated by a motor 34 via aclutch 35. The motor 34 is for advancing the recording paper placed inthe color thermal printer. The bias roller 53 is movably attached alonga groove 56 provided inside of the lower case 4 and biased toward thecorner of the lower case 4 by a spring 57 in order to tighten theendless belt 55. Thus, although a diameter of the paper roll changes,the endless belt 55 always contacts with a part of the outer peripheryof the paper roll 12 tightly.

Upon rotating the driving roller 52, the endless belt 55 is rotatedaround the three rollers 52, 53 and 54. When the endless belt 55 isrotated in counterclockwise direction in FIG. 2, the paper roll 12 isrotated in clockwise direction and the leading edge portion of therecording paper 11 is advanced to the outside of the paper magazine 2through the draw-out mouth 8. When the endless belt 55 is rotated in thereverse direction, the paper roll 12 is rotated in the counterclockwisedirection and the leading edge portion is wound up in the magazine mainbody 1. The leading edge portion is kept in a state that it is pressedto the paper roll 12.

A shutter operating device 27 shown in FIG. 2 is constituted of anactuating lever 31 for moving the shutter 15 up and down, a cam 32 foroperating the actuation rod 31, and a motor 33 for rotating the cam 32.The actuating lever 31 comprises a first link 15 a contacting theshutter 15 and a second link 15 b contacting the cam 32. The first link15 a and the second link 15 b are rotatably connected with a connectingshaft 15 c. Further, the second link 15 b is rotatably attached to amagazine loading section 26 at an axis portion 15 d.

When the shutter 15 is opened, the motor 33 is driven to rotate the cam32 in counterclockwise direction in FIG. 2. Due to the rotation of thecam 32, the second link 15 b of the actuating lever 31 is rotated inclockwise direction around the axis portion 15 d so that the first link15 a rises. A lower face of the shutter 15 is pushed up against the biasof the spring 17 so that the shutter 15 is moved to the open position.Accordingly, the draw-out mouth 8 emerges (refer to FIG. 4A). On theother hand, when the shutter 15 is closed, the motor 33 is rotated inreverse direction. Thus, the shutter 15 is pushed down by the bias ofthe spring 17 and moved to the close position to cover the draw-outmouth 8. The draw-out mouth 8 is closed in light-tight manner (refer toFIG. 4B).

FIGS. 3A and 3B are explanatory illustrations showing a schematicstructure of the color thermal printer. The paper magazine 2 is set onthe magazine loading section 26 disposed at the paper feed side. of thecolor thermal printer 25. The magazine loading section 26 is providedwith the shutter operating device 27 and the driving gear 28.

At a downstream side of the magazine loading section 26, a loop formingportion 46 is provided. The loop forming portion 46 contains therecording paper 11 in loop-like form when the recording paper 11 isdrawn back by a transporting roller pair 36. In this embodiment, theloop forming portion 46 is provided with a dancer roller 48 biased in anabove direction by a spring 47 or the like and the recording paper 11 ispushed up so as to get rid of slackness thereof as shown by broken linein FIG. 3A. In order to prevent the paper roll 12 from being rotated bytension of the dancer roller 48, proper rotational load is given to theendless belt 55.

At a downstream side of the loop forming portion 46, a cutter 37 forcutting the recording paper 11 is disposed. An upper blade of the cutter37 is movable and a lower blade thereof is fixed. After recording thefull color image, the upper blade of the cutter 37 is moved so that arecorded area of the recording paper 11 is cut away as a sheet with theupper blade and the lower blade.

At a downstream side of the cutter 37, the transporting roller pair 36is disposed. The transporting roller pair 36 nips the recording paperdrawn out from the draw-out mouth 8 to convey it. An upper one of thetransporting roller pair 36 is a capstan roller 36 a and a lower one theroller pair 36 is a pinch roller 36 b being movable in an up and downdirection. Moreover, a sensor 38 for detecting the leading edge of therecording paper 11 is provided at the side of the transporting rollerpair 36.

At a downstream side of the transporting roller pair 36, a platen roller39 made of hard rubber is rotatably provided. A thermal head 41 isrotatably provided, opposing to the platen roller 39. The thermal head41 presses and heats the recording paper 11 on the platen roller 39 torecord a full color image in three-color frame sequential process. Aswell known, the thermal head 41 comprises a plurality of heatingelements arranged in line in axial direction of the platen roller 39.

At a downstream side of the thermal head 41, an optical fixing unit 42is disposed. The optical fixing unit 42 comprises an ultraviolet lamp 42a for fixing yellow image and an ultraviolet lamp 42 b for fixingmagenta image. The ultraviolet lamp 42 a radiates the ultraviolet raysof which the wavelength is 420 nm and deprives the color ability of theyellow heat sensitive color layer. The ultraviolet lamp 42 b radiatesthe ultraviolet rays of which the wavelength is 365 nm and deprives thecolor ability of the magenta heat sensitive color layer.

At a downstream side of the optical fixing unit 42, a paper dischargeroller pair 43 is disposed. The paper discharge roller pair 43 nips theprint sheet cut in the sheet-like form and discharges it from a paperdischarge port 44 after full-color printing was over. Incidentally,reference numeral 45 denotes a guide plate forming conveyance passage ofthe recording paper 11.

Next, an operation of the above embodiment is described. The papermagazine 2 is set on the magazine loading section 26. In this state, thedriven gear 22 disposed outside of the paper magazine 2 meshes with thedriving gear 28.

Before printing, a main switch (not shown) of the color thermal printer25 is turned on. When the main switch is turned on, the motor 33 isdriven to rotate the cam 32 in counterclockwise direction in FIG. 2 sothat the second link 15 b of the actuating lever 31 is rotated aroundthe axis portion 15 d in a clockwise direction. The first link 15 arises and the shutter 15 is pushed up against the bias of the spring 17.Accordingly, the shutter 15 is moved to the open position and thedraw-out mouth 8 emerges (refer to FIG. 4A).

After image data for printing is taken in, paper feeding is started bythe instruction of a print via the operating section (not shown). Duringthe paper feeding, the motor 34 is driven to rotate the driven gear 22via the clutch 35 and the driving gear 28. Upon rotating the driven gear22, the driving roller 52 coaxially provided therewith is rotated andthe endless belt 55 is started to rotate in a counterclockwise directionaround the three rollers 52, 53 and 54.

When the endless belt 55 is rotated, the paper roll 12, a part of theouter periphery of which contacts the endless belt 55 tightly, isrotated in a clockwise direction with the endless belt 55. Thus, theleading edge portion of the recording paper 11 is conveyed to thedraw-out mouth 8 along the endless belt 55. Upon further rotation of theendless belt 55, the leading edge portion of the recording paper 11reaches the sensor 38 through the loop forming portion 46 and the cutter37. When the sensor 38 detects the leading edge, the sensor 38 sends asignal to a controller (not shown). When the controller receives thesignal, the transporting roller pair 36 is set in a nip state and therecording paper 11 is conveyed toward the thermal head 41. On the otherhand, counting is started when the leading edge is detected in order tomeasure an amount of the recording paper 11 drawn out.

While the recording paper 11 is fed, the thermal head 41 is separatedfrom the platen roller 39 and the recording paper 11 is conveyed towardthe optical fixing unit 42 through a gap therebetween. The drawn amountof the recording paper 11 is measured by a counter. From a value of thecounter, when it is judged that a cut position of the recording paper 11reaches an upstream edge of the optical fixing unit 42, the conveyingdevice 51 and the transporting roller pair 36 are stopped so thatfeeding of the recording paper 11 is stopped.

Successively, the controller rotates the motor 34 in a reverse directionto start a first draw-back operation of the recording paper 11 nippedwith the transporting roller pair 36. The recording paper 11 drawn backis contained in the loop forming portion 46 by moving the dancer roller48 in an above direction according to the draw-back amount thereof Whilethe recording paper 11 is drawn back, the clutch 35 is not connected sothat the endless belt 55 is stopped. Although the recording paper 11 ispulled due to the ascent of the dancer roller 48, the endless belt 55 isadapted to be not rotated with the paper roll 12 by rotational load ofthe endless belt 55.

When an end edge of a record area of the recording paper 11 approachesthe thermal head 41, the thermal head 41 is rotated to press therecording paper 11. After the thermal head 41 faced the end edge of therecord area, a print control unit (not shown) drives the thermal head 41in accordance with yellow image data to record the yellow image line byline. When the yellow image has been recorded on the record area of therecording paper 11 and the leading edge of the recording paper 11 isdetected by the sensor 38, draw-back operation of the recording paper 11is stopped. At the same time, the thermal head 41 is moved to a positionin that the recording paper 11 is not pressed.

After the thermal head 41 is moved, the controller rotates thetransporting roller pair 36 in the order direction again. The recordingpaper 11 contained in the loop forming portion 46 is advanced by aprescribed amount, lowering the dancer roller 48. At this time, theclutch 35 is not connected so that the endless belt 55 is still stopped.During the advancement of the recording paper 11, the ultraviolet lamp42 a for fixing yellow of the optical fixing unit 42 is turned on andthe ultraviolet ray of 420 nm is radiated in the record area of therecording paper 11 by a prescribed amount. Accordingly, the yellow heatsensitive color layer of the recording paper 11 loses its color ability.

Next, the second draw-back operation is started. When the end edge ofthe record area reaches the thermal head 41 again, the thermal head 41is rotated to press the recording paper 11 again. At this time, thethermal head 41 is driven in accordance with magenta image data so thatthe magenta image is recorded on the recording paper 11 one line by oneline. While the magenta image is recorded, the thermal head 41 generatesgreater thermal energy in comparison with the recording of the yellowimage.

After recording the magenta image, the recording paper 11 is advanced byprescribed amount as described above. The ultraviolet lamp 42 b forfixing magenta is turned on and the ultraviolet ray of 365 nm isradiated for the record area of the recording paper 11 by a prescribedamount. Thus, the magenta image is fixed.

During a third draw-back operation, the thermal head 41 generatesgreatest thermal energy in accordance with the cyan image data andrecords the cyan image on the record area of recording paper 11 line byline. After recording the cyan image, the thermal head 41 is moved awayfrom the recording paper 11. When the recording of the cyan image isover, a full color image is formed on the recording paper 11.

When the leading edge of the recording paper 11 is detected by thesensor 38, the third draw-back operation is over and the recording paper11 is advanced again. After that, when the cut portion of the recordingpaper 11 reaches the position of the cutter 37, conveyance of therecording paper 11 is stopped once. The cutter 37 is actuated to cut therecording paper 11 at the cut position. Thus, the recording paper 11 iscut away as a sheet-like print.

A leading edge of the sheet-like print reaches the paper dischargeroller pair 43. The roller pair 43 is rotated, nipping the sheet-likeprint, to discharge it from the paper discharge port to a tray or thelike. Finally, one full color print is completed.

In such a manner, full color prints are carried out by the necessarynumber. As the prints are carried out, a diameter of the paper roll 12contained in the paper magazine 2 decreases. The bias roller 53 of theconveying device 51 is pulled by the spring 57. Accordingly, as thediameter of the paper roller 12 decreases, the bias roller 53 is movedtoward the corner of the lower case along the groove 56. In other words,the whole of the endless belt 55 is pulled so that the endless belt 55between the driving roller 52 and the driven roller 54 always contactsthe outer periphery of the paper roll 12 tightly (refer to the chainline in FIG. 2).

After the full color prints are carried out by the necessary amount, auser turns off a main switch of the color thermal printer 25. At thistime, a power circuit of the color thermal printer 25 is not turned offat once and the conveying device 51 starts the draw-back operation ofthe recording paper 11. Namely, the motor 34 is rotated in the reversedirection and rotates the endless belt 55 in draw-back direction via theclutch 35. Accordingly, the paper roll 12 is rotated in thecounterclockwise direction in FIG. 2.

Upon rotating the paper roll 12 in the reverse direction, the recordingpaper 11 drawn in the color thermal printer 25 is wound up into thepaper magazine 2 through the draw-out mouth 8. When the leading edge ofthe recording paper 11 is drawn back and contacts the outer periphery ofthe paper roll 12 perfectly, the conveying device 51 is stopped. In thisstate, the leading edge of the recording paper 11 contacts the outerperiphery of the paper roll 12 tightly so that the whole of recordingpaper 11 including the leading edge is kept in uniform humidity whilethe thermal printer is not used.

After winding up the recording paper 11, the motor 33 is rotated in thereverse direction to rotate the cam 32 in the clockwise direction inFIG. 4A. As the cam 32 rotates in the clockwise direction, the shutter15 is pressed down by the bias of the spring 17 and moved to the closedposition to cover the draw-out mouth 8. Thus, the draw-out mouth 8 isclosed and the outside air and the ultraviolet rays are prevented fromentering the paper magazine (refer to FIG. 4B). Further, after theshutter 15 is moved to the close position, the power circuit of thecolor thermal printer 25 is turned off and the whole actuation of thecolor thermal printer 25 is stopped.

On the other hand, when the recording paper 11 set in the paper magazine2 is used up and the new recording paper roll 12 is loaded, the rollsupport shaft 7 is detached. The detached shaft 7 is inserted into thecore 12 a of the new recording paper roll 12 and set in the papermagazine 2 again, pressing the paper roll 12 against the bias of theendless belt 55.

In the above-described embodiment, the endless belt 55 has twofunctions, one of which is a function that the recording paper is woundup, and the other of which is a function that the recording papercontacts the outer periphery of the paper roll tightly up to the leadingedge thereof. However, as a paper magazine shown in FIG. 5, a windingdevice may be provided besides a contacting device.

The paper magazine 61 shown in FIG. 5 has a contacting device 60comprising three rollers 62, 63 and 64, and a belt 66, both ends ofwhich are pulled by a spring 65 to each other. A part of the belt 66 isfixed with a fixing member 59 so that the belt 66 does not rotate.However, as both ends are pulled by the spring 65, the belt 66 ismovable among the three rollers 62-64 by an amount corresponding to aslack thereof The belt 66 always contacts a part of the outer peripheryof the paper roll 12 tightly by urging of the spring 65 without regardto the diameter of the paper roll 12.

A magazine roller pair 69 comprising two magazine rollers 69 a and 69 bis provided near the draw-out mouth 8. The driven gear 22 is attached toone end of the magazine roller 69 b. The driven gear 22 meshes with thedriving gear 28 when the paper magazine 61 is set. A roll support shaft68 supporting the paper roll 12 is rotated by the motor 34 via theclutch 35. Incidentally, the structure of the shutter operating devicefor opening and closing the draw-out mouth 8, the structure of themagazine main body 1 and so forth are similar to that of the firstembodiment.

As to the paper magazine 61 having such a structure, when the print ofthe thermal printer is started, at the outset, the shutter 15 of theshutter unit 9 is moved to open the draw-out mouth 8. After that, theroll support shaft 68 is rotated by the motor 34 to rotate the paperroll 12 in the clockwise direction in FIG. 5. Thus, the recording paper11, the leading edge portion of which tightly contacts the outerperiphery of the paper roll 12 with the belt 66, is sent toward thedraw-out mouth 8, sliding on the belt 66. The leading edge of therecording paper 11 is nipped when it reaches the magazine roller pair 69being rotated. The recording paper 11 is fed to the thermal printer fromthe draw-out mouth 8 by rotating the roll support shaft 68 and themagazine roller pair 69.

When the prints of necessary number are printed, the roll support shaft68 and the magazine roller pair 69 start to rotate in the reversedirection so that the recording paper 11 drawn in the thermal printer iswound up in the paper magazine 61, sliding on the belt 66. When theleading edge portion reaches a position that the belt 66 contacts theouter periphery of the paper roll 12 tightly, the motor 34 is stopped.After that, the shutter 15 is moved to close the draw-out mouth 8. Alsoin this embodiment, the recording paper 11 tightly contacts the outerperiphery of the paper roll 12 up to the leading edge portion.

By the way, the magazine roller pair 69 may be omitted. In this case,advancement and drawing back of the recording paper 11 are performed byonly rotation of the roll support shaft 68. Further, in this case, it ispreferable to form a guiding passage for the recording paper near thedraw-out mouth of the paper magazine. Moreover, the number of therollers supporting the endless belt may be four or more, or two.

Further, a quadrilateral sheet may be used. In this case, one side ofthe sheet is fixed and the other side of the sheet is movable toward thecore in order to press the leading edge portion.

Besides the above embodiments, for example, a roller used as both of acontacting device and a winding device may be provided. A paper magazine71 shown in FIGS. 6A and 6B is provided with a roller 72, a groove 73and bias means 74. The roller 72 is used as both of a contacting deviceand a winding device. The groove 73 engages with the core 12 a of thepaper roll 12 and movably supports the paper roll 12 in an up-and-downdirection. The bias means 74 biases the paper roll 12 toward the roller72.

As to the paper magazine 71, as shown in FIG. 6A, when the print of thethermal printer is started, the shutter 15 is moved to open the draw-outmouth 8 and the roller 72 tightly contacting the outer periphery of thepaper roll 12 is rotated by a motor 75 in clockwise direction in FIG.6A. The recording paper 11 is sent out from the draw-out mouth 8 througha paper feed passage 76 and fed to the thermal printer.

During the print, the diameter of the paper roll 12 decreases by anamount of recording paper 11 drawn out from the paper magazine 71.Thereupon, the paper roll 12 is moved by the bias means 74 in thedownward direction along the groove 73 (refer to FIG. 6B). Accordingly,the roller 72 always contacts a part of the outer periphery of the paperroll 12 tightly and the recording paper 11 is steadily sent out.

When the prints of necessary number are printed, the roller 72 isrotated in the counterclockwise direction in FIG. 6B to pull therecording paper 11 sent out from the draw-out mouth 8 into the papermagazine 71. Then, when the leading edge portion of the recording paper11 is drawn back to a position of the roller 72, the roller 72 isstopped to rotate and, at the same time, the shutter 15 is closed (referto FIG. 6B). Detection of the recording paper 11 is carried out by asensor (not shown) disposed near the roller 72. Also in this embodiment,the recording paper 11 tightly contacts the outer periphery of the paperroll 12 up to the leading edge portion thereof. In this state, theleading edge portion of the recording paper 11 tightly contacts theouter periphery of the paper roll 12 with the roller 72 so that thewhole of recording paper 11 including the leading edge portion is keptat a uniform humidity while the thermal printer is not used.

As to each of the above embodiments, opening and closing of the shuttermay be performed for every print. Further, with respect to the openingand closing of the shutter, the shutter may be automatically closedafter the prints of a predetermined number were printed. Moreover, aswitch for opening and closing the shutter may be provided to open andclose the shutter at the user's discretion (only when the print isperformed). In this case, it is desirable that the opening and closingof the shutter are detected by a sensor or the like in order that theprinting may be capable only when the shutter is opened and the shuttermay be closed only when the recording paper is perfectly wound in thepaper magazine up to the leading edge thereof.

In the above embodiments, the color heat sensitive recording paper isused as a recording paper. However, besides that, various recordingpapers requiring light shield and damp proof, for example, aphotographic paper having photosensitivity and so forth, may be used.

FIG. 7 shows another embodiment of the paper magazine according to thepresent invention. A magazine roller pair 85 comprising two magazinerollers 85 a and 85 b is rotatably attached inside the paper magazine 2and near the draw-out mouth 8. The magazine rollers 85 a and 85 b comeinto contact with each other. The magazine rollers 85 a and 85 b nip therecording paper 11 to draw out it from the paper roll 12 and send it tothe color thermal printer through the draw-out mouth 8. One end of ashaft of the magazine roller 85 a penetrates the lower case 4 andreaches the outside. The driven gear 22 is fixedly secured to the oneend of the shaft and meshes with the driving gear 28 provided in thecolor thermal printer. The magazine roller pair 85 is rotated inassociation with the paper advancement performed in the color thermalprinter.

A roll remainder indicator 80 for indicating the remainder of the paperroll 12 is attached to the upper case 3 of the paper magazine 2. Theroll remainder indicator 80 comprises an arm 81, a coil spring 82, anindicating member 83 and a scale plate 84. The arm 81 contacts the outerperiphery of the paper roll 12. The coil spring 82 biases the arm 81 soas to press it to the outer periphery of the paper roll 12. Theindicating member 83 is fixedly secured to one end of the arm 81projecting out of the main body 1. The scale plate 84 is stuck on theupper case 3.

The arm 81 has L-like shape and one end of which is rotatably attachedto the upper case 3. A rotatable roller 81 a made of rubber or the likeis attached to the other end of the arm 81 so as to contact the outerperiphery of the paper roll 12. On the scale plate 84, there are writtenscales at equal intervals from “F” representing the remainder of theunused state to “E” representing a state that the remainder of the paperroll 12 has run out. The indicating member 83 points to one of thescales so that the remainder is indicated.

The roller 81 a of the arm 81 is always pressed to the outer peripheryof the paper roll 12 by the bias of the coil spring 82. At this time,the biasing force of the coil spring is minimized and the roller 81 acontacts the paper roll 12 so that the recording paper 11 is not damagedby the indicating device 80.

When a new recording paper roll 12 is loaded in the paper magazine 2,the upper case 3 of the paper magazine 2 is rotated to open the mainbody 1, centering around the contact portion 5. The roll support shaft 7is detached from the paper magazine 2 and inserted into the core 12 a ofthe paper roll 12. The roll support shaft 7 is set in the main body 1again with the paper roll 12. Further, the recording paper 11 isslightly drawn by rotating the paper roll 12 and the leading edgethereof is put in the magazine roller pair 85 to be nipped.

When the upper case 3 is rotated to close the main body 1, as shown inFIG. 8A, the arm 81 biased in counterclockwise direction by the coilspring 52 contacts the outer periphery of the paper roll 12. Uponclosing the upper case 3 completely, the indicating member 83 attachedto one end of the arm 81 points to the position “F” of the scale plate84. Accordingly, the indicating member 83 indicates that the wholeamount of the paper roll 12 remains.

As the printing is performed, the diameter of the paper roll 12decreases. The arm 81, the roller 81 a of which always contacts theouter periphery of the paper roll 12, is rotated in a counterclockwisedirection in accordance with the decrease of the diameter of the paperroll 12. Thus, the indicating member 83 attached to one end of the arm81 is moved on the scale plate 84 toward the position “E”.

Due to observing a position of the scale plate 84 pointed by theindicating member 83, a user can recognize the remainder of the paperroll 12 without opening the light-tight paper magazine 2.

As shown in FIG. 8B, when the remainder of the paper roll 12 almost runsout, the indicating member 83 is moved to the near place of the position“E” of the scale plate 84. The user exchanges the paper roll 12 when theindicating member 83 comes near the position “E” of the scale plate 84.Accordingly, there does not arise a problem in that the printing iscontinued although the remainder of the paper roll 12 almost runs outand the recording paper runs out during the printing.

In the above embodiment, the roller 81 a is provided at the top end ofthe arm 81 of the indicating device 80. However, the arm 81 may contactthe outer periphery of the paper roll directly without the roller 81 a.In this case, it is preferable that the biasing force of the arm 81 isweakened so as not to rub the rear face of the recording paper with thearm strongly. Moreover, in the above embodiment, the arm 81 is biasedtoward the outer periphery of the paper roll by the coil spring 82.However, the arm 81 may contact the outer periphery of the paper rolldue to its own weight without biasing the arm.

In the above embodiments, the shutter of the paper magazine opens andcloses the draw-out mouth due to ON and OFF operation of the main switchof the color thermal printer. However, the shutter may be opened andclosed in association with attachment and detachment of the papermagazine. For example, as to a paper magazine 111 for a heat sensitiverecording paper roll 110 shown in FIGS. 9A and 9B, a shutter 115 of ashutter unit 114 is opened by an operating member 113 protruding on amagazine loading section 112 of the color thermal printer when the papermagazine 111 is set on the magazine loading section 112.

The shutter unit 114 having similar construction to the above embodimentis provided in front of a draw-out mouth 117 for drawing out a heatsensitive recording paper 116 from the paper magazine 111. The shutter115 is movably attached to the shutter unit 114 in up and downdirection, and biased toward a close position by means of a spring 118.Thus, the draw-out mouth 117 is covered with the shutter 115 when thepaper magazine 111 is not set in the thermal printer (not shown) so thatthe inside of the paper magazine 111 is kept in light-tight state andhumidity does not enter the paper magazine 111 (refer to FIG. 9A).Accordingly, it does not occur that the paper roll 110 is exposed to thelight and desired color density can not be obtained due to the humidity.

When the paper magazine 111 is set on the magazine loading section 112of the thermal printer, the operating member 113 protruding on themagazine loading section 112 contacts the lower portion of the shutter115 and pushes it up against the bias of the spring 118 (refer to FIG.9B). Thus, the draw-out mouth 117 emerges so that it becomes possible todraw out the recording paper 116 and perform the thermal recording. Whenthe paper magazine 111 is detached from the magazine loading section112, the shutter 115 is released from the press of the operating member113 and lowered to the closed position by mean of the spring 118 so thatthe draw-out mouth 117 is closed.

In the above-described embodiment, as the mechanism for opening andclosing the shutter 115, the operating member 113 for pushing theshutter up is merely provided on the magazine loading section 112.Accordingly, the operating mechanism for the shutter may be constructedin a simple manner and at a low cost. Further, the shutter 115 may becertainly opened and closed in association with attachment anddetachment of the paper magazine 111. Alternatively, the shutter 115 maybe opened and closed by hand.

Next, FIG. 10 shows another embodiment of the paper magazine accordingto the present invention. At an inside lower portion of the papermagazine 2, a space is formed so as to contain the recording paper 11 ina loop-like state when the recording paper 11 is drawn back in theprocess of printing. A humidity conditioning paper 90 is provided on atray 4 a which is formed inside of the lower case 4. The tray 4 a isintegrally formed with the lower case 4. The humidity conditioning paper90 is made of a humidity conditioning material keeping the inside of thepaper magazine at a constant humidity.

As the humidity conditioning paper 90, for example, there is SHC (SuperHumidity Controlling) paper (trade name, manufactured by Tokushu SeishiCo., Ltd.) disclosed in “Polyfile” (March 1994, Vol. 31, No. 361, pp.56-58) and “TRIggER” (May 1993, Vol. 12, No. 5, pp. 60-63). The humidityconditioning paper 90 comprises a porous inorganic powder material andcellulose fiber. Preprocess is performed for the humidity conditioningpaper. The humidity conditioning paper is left in a predeterminedhumidity environment more than four hours before using it. After that,the humidity conditioning paper 90 is mounted in a conditioned space.

When the space in which the humidity conditioning paper 90 is mountedbecomes a higher humidity than the predetermined humidity, the humidityconditioning paper 90 absorbs moisture in the space. The absorption ofmoisture is rapidly performed until the space becomes the predeterminedhumidity environment. On the other hand, when the space becomes a lowerhumidity than the predetermined humidity, moisture absorbed in thehumidity conditioning paper 90 is released in the space. Thehumidification is performed until the space becomes the predeterminedhumidity environment. Accordingly, the space is kept at predeterminedhumidity environment. As to the amount used for the humidityconditioning paper 90, 1-2 Kg per 1 m³ for the space is preferable.

The humidity conditioning paper 90 set on the tray 4 a is left in anormal humidity environment of 60% RH for more than four hours. Thenormal humidity environment has a humidity at which the recording paper11 colors based on the prescribed color property. When the interiorhumidity of the paper magazine 2 is higher than the normal humidity, thehumidity conditioning paper 90 performs absorption of the moisture. Whenthe interior humidity is lower than the normal humidity, humidificationis performed by the humidity conditioning paper 90. Accordingly, theinterior humidity of the paper magazine 2 is always kept at a normalhumidity.

The humidity conditioning paper 90 has a honeycomb structure in order toexpand the surface area thereof and perform the humidity conditioning inan efficient manner. The humidity conditioning paper 90 maintains theprescribed humidity conditioning ability for about five years ingeneral. When the humidity conditioning ability is reduced, a newhumidity conditioning paper 90 for which preprocess is performed is seton the tray 4 a.

FIG. 11 shows an embodiment in that a core made of a humidityconditioning material is employed. A thermal recording paper roll 91consists of a film-like color thermal recording paper 92 wound aroundthe core 93. The core 93 is made such that the humidity conditioningmaterial, for example, the humidity conditioning paper is formed in acylindrical shape. As described above, the SHC paper and so forth areused as the humidity conditioning paper.

For the core 93, a preprocess is performed. The core 93 is left in thenormal humidity environment for more than four hours when the paper roll91 is manufactured. The normal humidity environment has a humidity atwhich the recording paper 92 colors in the most suitable density. Afterthat, the recording paper 92 is wound around the preprocessed core 93and the paper roll 91 is manufactured.

As described above, the core 93 of the paper roll 91 is made of thehumidity conditioning paper. Accordingly, by setting the paper roll 91to an attachment rod 95 of the paper magazine in which the humidityconditioning material is not provided, the inside of the paper magazineis kept at a normal humidity due to the humidity conditioning functionof the core 93.

Moreover, whenever a new recording paper roll 91 is set to the papermagazine, the core 93 is exchanged therewith so that the humidityconditioning of the paper magazine is always performed by a new humidityconditioning material. Accordingly, it is not necessary to pay attentionto the exchange of the humidity conditioning material.

In the above-described embodiments, the SHC paper is used as an exampleof the humidity conditioning material. However, this is not exclusive.Other humidity conditioning materials having similar characteristic maybe used.

Next, FIG. 12 shows another embodiment of the paper magazine accordingto the present invention. In FIGS. 12 and 13, a box-type paper magazine122 comprises a case main body 123 and a case lid or cover 124. An upperportion of the case main body 123 is opened. The cover 124 is rotatablyattached to the case main body 123 via a hinge portion 125. The papermagazine 122 is made of plastic having a light shielding property inorder to contain a recording paper roll 132 of a color thermal recordingpaper 131 having a heat sensitive property and ultraviolet fixingproperty. On both side faces 123 a and 123 b of the case main body 123,U-shaped bearings 127 a and 127 b, an upper portion of which is opened,are integrally formed. Three plate springs 130 a, 130 b and 130 c areattached to the side face 123 a of the case main body 123. The platesprings 130 a-130 c are disposed on a concentric circle centering aroundthe bearing 127 a at equal intervals. At front lower portion of the casemain body 123, there is provided a draw-out mouth 128 for drawing outthe recording paper 131 and feeding it to the color thermal printer.

The film-like recording paper 131 is wound around a core 129 made ofpaper or plastic to constitute the paper roll 132. When the paper roll132 is loaded in the paper magazine 122, flanges 133 and 134 are fittedinto the core 129 from right and left thereof. The flange 133 isconstituted of a circular flange portion 133 a, a shaft portion 133 band a support portion 133 c. The shaft portion 133 b and the supportportion 133 c are respectively provided on both sides of the flangeportion 133 a. The other flange 134 is similar to the flange 133 so thatdescription about it is omitted although reference numerals are given as134 a (circular flange portion), 134 b (shaft portion), and 134 c(support portion). The paper roll 132 is caught between the flangeportions 133 a and 134 a. Accordingly, the recording paper 131 isprevented from meandering when it is drawn out.

In the paper magazine 122, three points located on the concentric circleof the flange portion 133 a are uniformly pushed by the plate springs130 a-130 c. Thus, the flanges 133 and 134 are pushed toward the bearing127 b in a state that the flanges 133 and 134 catch both sides of thepaper roll 132. Accordingly, the paper roll 132 is prevented fromchanging its position due to looseness of the flanges 133 and 134.Further, suitable back tension is given to the paper roll 132 byfriction of the plate springs 130 a-130 c and the flange portion 133 a.Incidentally, the strength of the back tension may be easily changed bychanging the spring force of the plate springs 130 a-130 c.

When the paper roll 132 is loaded in the paper magazine 122, the supportportions 133 c and 134 c of the flanges 133 and 134 are fitted into thecore 129 and the flange portions 133 a and 134 a are put on the sideface of the paper roll 132. Next, the shaft portions 133 b and 134 b ofthe flange 133 and 134 are fitted into the bearings 127 a and 127 b ofthe case main body 123 from the top thereof. After the leading edge ofthe recording paper 11 passed through the draw-out mouth 128, the casemain body 123 is covered with the case cover 124 and locked by a lockmechanism (not shown) so as not to be opened.

The plate springs 130 a, 130 b and 130 c contact the side face of theflange portion 133 a and press it so that the paper roll 132 is pressedtoward the side face 123 b of the case main body 123. Thus, the paperroll 132 is held at a prescribed position of the paper magazine 122without looseness.

The plate springs 130 a, 130 b and 130 c are disposed on the concentriccircle about the rotational center of the paper roll 132 so as toposition them around the bearing 127 a. Accordingly, the flange portion133 a is uniformly pressed and the recording paper 131 is drawn out in astable state. Moreover, prescribed back tension is applied to therotation of the paper roll 132 by means of the bias of the plate springs130 a, 130 b and 130 c.

In the above embodiment, the plate springs 130 a-130 c are attached tothe case main body 123. However, for example, the plate springs may beprovided on the flange as shown in FIG. 14.

As to a paper magazine 141, plate springs 142 a, 142 b and 142 c areprovided on a flange portion 143 a of a flange 143. Thus, the platesprings 142 a-142 c attached to the flange portion 143 a press the sideface 123 a of the case main body 123 so that the paper roll 132 caughtbetween the flanges 143 and 144 is pushed toward the side face 123 b ofthe case main body 123.

By such a structure, the paper roll 132 is kept in the paper magazine141 without looseness and the recording paper 131 may be drawn outstraight without meandering. Further, suitable back tension is appliedto the paper roll 132 due to the bias of the plate springs 142 a-142 cso that the paper roll 132 is not needlessly rotated by inertia when thedrawing of the recording paper is stopped. Moreover, it is not necessaryto provide an expensive clutch device and a precision bearing mechanismso that the paper magazine may be manufactured with a simple structureand at low cost.

Although the present invention has been fully described by way of thepreferred embodiments thereof with reference to the accompanyingdrawings, various changes and modifications will be apparent to thosehaving skill in this field. Therefore, unless otherwise these changesand modifications depart from the scope of the present invention, theyshould be construed as included therein.

What is claimed is:
 1. A paper magazine for a thermal recording paperroll in which a roll of a thermal recording paper, which is opticallyfixed by ultraviolet rays and a color property of which changesaccording to humidity, is rotatably contained, said paper magazine beingremovably attached to a thermal printer and provided with a draw-outmouth through which said thermal recording paper is drawn out and fed tosaid thermal printer, said paper magazine comprising: a shaft whichsupports said thermal recording paper roll; a shutter for closing saiddraw-out mouth; and a humidity conditioning material disposed in saidpaper magazine, said humidity conditioning material absorbing moisturewhen an inside of said paper magazine closed with said shutter is highin humidity and performs humidification when said inside of said papermagazine is low in humidity.
 2. A paper magazine according to claim 1,wherein said humidity conditioning material is fixed in said papermagazine.
 3. A paper magazine according to claim 1, wherein saidhumidity conditioning material is a humidity conditioning paper in whichporous materials are kept among cellulose fibers.
 4. A paper magazineaccording to claim 1, wherein said humidity conditioning material isdisposed in said paper magazine in a form of a core around which saidroll is wound.